How much space is enough? Aussies ask.

Australia's population is set to grow 65 percent by 2050, a prediction that has many worried.

The year leading up to June 2009 saw a record population growth of 2.1 percent, the bulk of it coming from immigration. Economists say that the spike in numbers helped brace the country against the global financial crisis. In 2009, Australia boasted a 2.7-percent growth in GDP and a low unemployment rate of 5.3 percent.

"Population growth to a major extent underpins the domestic growth story," James Craig, chief equities economist at CommSec, told Reuters. "More people translates to increased spending and demand for homes, and as a result, increased momentum for our economy."

But the demand for homes has resulted in a 20-percent jump in housing prices in the last year, according to the Australian Bureau of Statistics. It is just one of the many concerns that Australians have with a bigger nation.

“A lot of people are finding the idea of adding 2 million or more to our current cities confronting,” said Fergus Hanson, a research fellow from the Lowy Institute for International Policy, who conducted a poll, surveying Australia’s thoughts on population growth. Sixty-nine
percent of Australians want the population to be 30 million, or less, in 40 years time. “People are worried about congested roads, infrastructure problems and strain on environmental resources.”

“Australians like their space,” said Saul Eslake the program director at the Grattan Institute, a Melbourne-based think tank. “We aren’t like Asians or even New Yorkers, but more like Texans, in the way we enjoy space. And if Sydney or Melbourne’s populations do hit 7 million, then the way we use space will change dramatically.”

Eslake warns against growth in GDP as an indication of a country’s wealth: “Yes, a higher population will lead to a higher GDP, but that doesn’t necessarily mean that the GDP per person will increase, in all likelihood it won’t.”

The environmental impact of a large population will also be significant. Australia is the biggest emitter of carbon dioxide per capita, according to Maplecroft, a U.K.-based risk-assessment company. The Australian government has aimed to reduce these emissions by 60 percent on 2000 levels, by 2050.

“If growth follows the current trajectory, then our environmental resources will be overwhelmed,” said Ernest Healy a senior research fellow at the Center for Population and Urban Research at Monash University. “Meeting the target will be close to impossible.”

Even if emissions are under control, water will present another challenge. For three years in every decade Australia suffers from low rainfall, and in the next 20 years the demand for water in Australia will rise dramatically. In western Australia alone, the jump in total water use across the state will be 2,300 gigaliters to 3,900 gigaliters.

“We have a very large, and very dry continent,” said Healy. “But in terms of resources, it’s actually very small. The coastal fringe is limited, it won’t be long before it gets too crowded.”